There is a alot of cross licensing in the tools industry, for parts and designs. ALOT of manual cutters use almost the exact same bases for example. The base on the new Rubi T and that of the Montolit Masterpiuma, are really similar, but they're entirely different machines.
Another example is the Tomecanic Supercut and the Nuovo Super Pro. The main part of the moving breaker on both of them, are almost identical. The Tomecanic crew has added some gadgets though.
Yet another example, is my mixing drill. It's got a design which is almost identical to that of the Rubi mixer you bought, but mine was alot cheaper. It's essentially a cheaped down version of one of the simpler Collomix hand mixers. The differance is just that. It's cheaped down. The wattage on it is much higher than on the Collomix equivialent (1600, compared to 1000), to compensate for lower torque.
You've probably not been ripped off. If you want to be ripped off, you could buy a
Berg mixer. Those are pure crap, at an even higher price. I know this from experience. Mine broke, from
tipping over. Enter-the-plastic type of experience that.